Urine test kit, containing various urinary test tablets, in red leather case, by Parke Davis and Co.

The amount of urea in urine was detected and measured by a simple chemical test. Urea was identified in the 1800s as a breakdown product of the proteins in the body. Pharmaceutical companies such as Parke-Davis and Company, who made this example, soon manufactured small portable test kits for doctors to use at the patient’s bedside. Tests for levels of urea indicate to physicians how well a person’s kidneys work. Waste products cannot be removed from the blood when a person’s kidneys fail. This causes illness. The ureometer comes in a red leather case with various urinary test tablets. These include potassium, lead oxide and citric acid.